It is generally known that in configuring a motor vehicle with a fuel tank, it is important to prevent the fuel tank from damage and spillage during the crash. There are several strategies that have been employed in automotive design to meet those desires and requirements.
Those strategies include, but are not limited to, placing the fuel tank away from the perimeter of the vehicle, ensuring crush space is provided to absorb crash energy before the fuel tank is affected, constructing the fuel tank of materials that are not easily cut or torn, applying shields in areas of the fuel tank that may be vulnerable, routing all supply lines in protected areas, and providing the filler with a check valve to prevent leakage. In addition, many fuel tanks are positioned in large cages or structures which are designed to absorb the impact of a crash or event. Other than attempting to absorb the impact, known systems do not use the energy of the impact to move the fuel tank downwardly and/or laterally to a position in which the fuel tank is either out of the path of the impact or protected by the chassis of the vehicle.
Automobiles and light trucks must pass standards for fuel tank leakage in all mandated crash tests that range from frontal impacts to side impacts to rear impacts. However, these standards do not require that the fuel tanks be moveable away from the frame of the vehicle during a collision or other such event. In addition, heavy trucks other than school buses have no federal requirements for crashworthiness of the fuel system.
Currently, most manufacturers of heavy trucks mount thin wall aluminum or steel tanks to the outside of the frame rails for carrying fuel. Due to the location and construction of the fuel tanks in heavy trucks, the tank is exposed to crushing during various crash events, resulting in an increased possibility of fuel spillage, fire and explosion. These risks are a known hazard in fuel storage areas of vehicles and are considered significant if there is an accident causing an object, such as, but not limited to, debris from an accident or guide rail, to penetrate the fuel tank. Rupturing of fuel tanks is believed to be a common reason for fires or explosions.
It would be desirable to provide a vehicle fuel tank system which overcomes the problems stated above. It would also be desirable to provide for revised placement and protection for the fuel tanks and fuel system, allowing the vehicle and the fuel tanks to manage the energy generated by a collision or event, such as, but not limited to allowing the fuel tank to be moved relative to or away from the frame of the vehicle during a collision or similar event, thereby improving crashworthiness and reducing the occurrence of tank failure, fuel spillage, fire and/or explosion.